linux-kernel - [PATCH] dmaengine: tegra20: Fix runtime PM imbalance in tegra_dma_issue

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Date:   Thu,  8 Apr 2021 15:11:57 +0800
From:   Dinghao Liu <dinghao.liu@....edu.cn>
To:     dinghao.liu@....edu.cn, kjlu@....edu
Cc:     Laxman Dewangan <ldewangan@...dia.com>,
        Jon Hunter <jonathanh@...dia.com>,
        Vinod Koul <vkoul@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        dmaengine@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] dmaengine: tegra20: Fix runtime PM imbalance in tegra_dma_issue_pending

pm_runtime_get_sync() will increase the rumtime PM counter
even it returns an error. Thus a pairing decrement is needed
to prevent refcount leak. Fix this by replacing this API with
pm_runtime_resume_and_get(), which will not change the runtime
PM counter on error.

Signed-off-by: Dinghao Liu <dinghao.liu@....edu.cn>
---
 drivers/dma/tegra20-apb-dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 71827d9b0aa1..73178afaf4c2 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -723,7 +723,7 @@ static void tegra_dma_issue_pending(struct dma_chan *dc)
 		goto end;
 	}
 	if (!tdc->busy) {
-		err = pm_runtime_get_sync(tdc->tdma->dev);
+		err = pm_runtime_resume_and_get(tdc->tdma->dev);
 		if (err < 0) {
 			dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
 			goto end;
-- 
2.17.1